The affix ktvā optionally gets the iṭ augment after a root which has an indicatory short u,
As शमु - शमित्वा or शान्त्वा; तमु - तमित्वा or तान्त्वा; दमु -दमित्वा or दान्त्वा ॥,
उदितो वा
Adhyāya 7 · Pāda 2 · Rule 56
Adhyāya 7 · Pāda 2 · Rule 56
The affix ktvā optionally gets the iṭ augment after a root which has an indicatory short u,
As शमु - शमित्वा or शान्त्वा; तमु - तमित्वा or तान्त्वा; दमु -दमित्वा or दान्त्वा ॥,